I know there has been some talk about the gravedigger in Force Awakens and who he would be. Some have speculated that Kylo Ren would be the Gravedigger and others think that Max von Sydow's character may be him. What if Luke Skywalker is the Grave Digger? With Luke being secluded, he's bound to do something behind the closet. Thinking back to Mark's role as the Joker, Joker has had various aliases, one of them being Oberon Sexton in Batman and Robin(When Grayson took over as Batman and Damian as Robin). As Oberon Sexton/Joker, He was the grave digger. With Mark Hamill being both Luke Skywalker and the Joker, What if JJ tries to tie the idea into Luke Skywalker and he becomes the Grave Digger in Force Awakens? It was also mentioned that Luke spent some time in the Dark side, so why not make him a good candidate for the role?

Your Lord knows very well what is in your heart. Your soul suffices this day as a reckoner against you. I need no witnesses. You do not listen to your soul, but listen instead to your anger and your rage.